1. Dental Materials Lecture
INLAY CASTING WAX
Dental Materials Lecture
BDS II Year
Dr. Raghuwar D Singh
Associate Professor
Prosthodontic Department
King George’s Medical University UP, Lucknow

2. First procedure in the casting of an inlay or crown is the preparation of a wax pattern.
TECHNIQUES for WAX PATTERN Preparation::
* Direct Technique
* Indirect Technique

3. TYPES OF INLAY CASTING WAX --
* According to ADA Specification No. 4 ::
TYPE I = Medium Wax for Direct Technique
TYPE II = Soft Wax for Indirect Technique

4. COMPOSITION Paraffin wax = 40 to 60 % Gum dammar Carnauba wax
Coloring agent

5. PARAFFIN WAX :
* Derived from high boiling fraction of petroleum.
* Depending upon Molecular Wt. & Distribution can be obtained in a wide melting or softening range.
* Paraffin used for Type I waxes have higher melting point than the Paraffin used for Type II waxes.

6. DISADVANTAGES –
Flake when it is trimmed.
Does not present Smooth, Glossy surface.

7. GUM DAMMAR or DAMMAR RESIN :
Natural Resin.
Added to improve the smoothness in molding.
Resistant to Cracking & Flaking.
Increases the Toughness of the wax.
Enhances the Smoothness of the surface.

8. CARNAUBA WAX :
Occurs as fine powder.
Quite Hard in nature.
High Melting point.
Combined with paraffin to Decrease the flow
at mouth temperature.
Give more Glossiness to wax surface than
dammar resin.

9. CANDELILLA WAX can also be added to replace the Carnauba wax.
Its Melting point is lower.
Not as hard as Carnauba wax.
CERESIN may replace part of Paraffin to modify
the toughness & carving characteristics of wax.

10. In modern Inlay Waxes, the Carnauba Wax is
often replaced in part with certain Synthetic
Waxes that are compatible with Paraffin wax.
Two waxes of this Types are ::
Complex Nitrogen derivatives of higher fatty
acids.
Esters of acids derived from Montan wax.

11. PROPERTIES OF INLAY WAX
When softened wax should be uniform.
Color should contrast with the die material.
No Flakiness or similar surface roughness when wax is bent & molded after softening.

12. Should Vaporize completely during burnout
Wax should not pull or chip during carving.
Wax pattern should be completely rigid &
dimensionally stable.

13. FLOW
THERMAL PROPERTIES
WAX DISTORTION
MANIPULATION OF INLAY WAX
OTHER DENTAL WAXES

14. FLOW –
Requirements according to ADA Specification no. 4,
At 450C -- Both Type I & II should have a flow b/w
70 to 90 %.
At 370C -- Type I should not flow more than 1 %.
At 300C -- Type II should not flow more than 1 %.

15. THERMAL PROPERTIES –
THERMAL CONDUCTIVITY :
Low.
Takes time to heat the wax uniformly.

16. COEFFICIENT OF THERMAL EXPANSION :
High.
Thermal changes are higher than any other materials.
Linear expansion of 0.6 % when heated from 25
to 370C is permitted for Type I waxes.
This property is more significant in Direct Tech.

17. * Other Factors that influence the Coefficient of
Thermal Expansion are –
Temperature of the Die.
Method used for applying pressure to the wax.

18. WAX DISTORTION –
Most serous problem in Inlay wax.
It is due to Release of Stresses in pattern due to,,
* Contraction on cooling.
* Occluded gas bubbles.
* Change of shape of wax during moulding.
* From Manipulation, Carving, Pooling &
Removal.

19. CAUSES OF DISTORTION :
If wax is not at uniform temp. when inserted in the cavity.
If wax is not help under uniform pressure during cooling.
If wax is added in an area of deficiency.

20. TO AVOID DISTORTION OF WAXES :
Minimal carving & change in temperature.
Minimal Storage of pattern.
Use warm instrument for carving.
Store it in a Fridge if necessary.

21. MANIPULATION OF INLAY WAX
TECHNIQUES –
DIRECT TECHNIQUE
INDIRECT TECHNIQUE

22. DIRECT TECHNIQUE ::
Softened the stick of wax over the flame.
Inserted into the cavity & held under finger
pressure.
Allow to cool gradually at mouth temperature.
Withdraw the wax pattern carefully.

23. INDIRECT TECHNIQUE ::
Pattern is prepared over a lubricated die.
If molten wax used, very little stresses occur.

24. METHODS OF INDIRECT TECHNIQUE –
Dipping Method –
* In full crowns.
* Die is dipped in hot liquid wax.
Softening In Warm Water – Not recommended.
Adding in Layer – Using spatula or brush.

25. OTHER DENTAL WAXES

26. RPD WAXES
PRECESSING WAXES
* Boxing & Beading Waxes.
* Utility Wax.
* Sticky Wax.
IMPRESSION WAXES
* Corrective impression Wax
* Bite Registration Wax

27. RPD WAXES To make patterns of metallic framework of RPD.
USES –
To make patterns of metallic framework of RPD.
Pattern for RPD is made on a special cast known as the Refractory Cast.

28. SUPPLIED AS --
* Sheets and .32 mm thickness.
* Readymade shapes, Round, Half round
Grid or Meshform
Clasp shapes
Other forms.
* Bulk.

29. PROPERTIES –
Highly Ductile, as they must adapt easily and
stick onto the refractory cast.
Must Vaporize during burnout.

30. BASEPLATE WAX or MODELING WAX
Supplied as,
Sheets of pink or red colour.

31. USES –
To make Occlusion rim.
To form the desired contour of denture after
teeth are set.
To make patterns for Orthodontic appliances.

32. CLASSIFICATION –
Type I = Soft ; for building Veneers.
Type II = Medium
Type III = Hard

33. COMPOSITION –
Paraffin wax or Ceresin = 80 %
Beeswax = 12 %
Carnauba wax = 2.5 %
Natural or Synthetic resin = 3 %
Microcrystalline = 2.5 %

34. PROCESSING WAX
** Used mainly as accessory aids.

35. Examples are ,
Boxing Wax & Beading Wax.
Utility Wax.
Sticky Wax.

36. BOXING & BEADING WAX USES --
To build up vertical walls around the impression.
SUPPLIED AS –
Boxing wax as sheets.
Beading wax as strips.

37. UTILITY WAX Supplied as – Sticks and Sheets.
Uses – To adjust the contour of perforated tray.
Composition – Petrolatum & other waxes.
** It is adhesive and can stick to the tray.

38. STICKY WAX USES -- To join metal parts before soldering.
To join fragments of broken dentures before
repair.

39. COMPOSITION --
Mainly Yellow Beeswax, Rosin & Natural resins such as Gum dammer.
PROPERTIES –
Sticky when melted & Adheres closely to surface.
Firm and Brittle at room temperature.

40. IMPRESSION WAXES
Used to record non – undercut edentulous portions of the mouth.
Examples are ,
** CORRECTIVE IMPRESSION WAX
** BITE REGISTRATION WAX

41. CORRECTIVE IMPRESSION WAX
USES --
To make functional impression of RPD.
To record Posterior Palatal Seal.
Functional Impression for Obturatures.

42. COMPOSITION --
Paraffin wax
Ceresin wax
Beeswax
May contain metal particles.
PROPERTIES –
FLOW at 37 0 C is 100 %.
Should be poured immediately.

43. BITE REGISTRATION WAX USES --
To record the relationship between the upper and
lower teeth.
SUPPLIED AS U shaped rods.
COMPOSITION Beeswax, Paraffin, Ceresin.

44. MCQs 1. The role of gum dammar in Inlay casting wax is:
a) To improve cracking resistance
b) To provide strength to wax
c) To impact smoothness to pattern
d) All of the above

45. 2. Carnauba was is preffered to candelila wax as:
It is harder and has less flow
It has low melting temperature
It provides luster to the pattern
All of the above

46. 3. Inlay wax should have following requisites:
Its colour should be in contrast with tooth or die material
It should have capability to be carved according to tooth anatomy and there should be no flaking.
When heated, it should be completely eliminated from the mould.
All of the above.

47. 4. Which of the following waxes is used for making of casting pattern:
Boxing wax
Inlay wax
Modeling wax
Utility wax

48. 5. The minimum flow of inlay wax at 450C should be:
60% 6%
70%
100%

49. 6. Which of the following correctly describe type I inlay casting wax:
Soft wax used for direct technique
Medium wax used for indirect technique
Soft wax used for indirect technique
Medium was used for direct technique

50. 7. The maximum ingredient of inlay casting wax:
Paraffin wax
Ceresin
Carnauba wax
Gum dammar

51. 8. Which of the following is added inlay casting was to improve the smoothness:
Ceresin
Candellila wax
Gum dammar
Synthetic wax

52. 9. Percentage of Carnauba wax in inlay casting wax is:
40%
60%
25%
10%

53. 10. Inlay casting wax is supplied as:
Sheets only
Mesh form only
Both of the above
None of the above